Does it say why you cannot change country? The article Change your Apple Account country or region - Apple Support describes how to change your Apple ID country or region, and the requirements and results of doing this.
You may encounter various issues and here is how to deal with them:
● Remove all your Apple Account balance using one of these two ways (if you use the first one you do NOT need to contact Apple):
- Add a credit or debit card to your account and buy items (not subscriptions) just in excess of your remaining balance. This will use all the balance and any excess will get charged to the card.
- Use the link in this article --> Check your Apple Account balance - Apple Support to contact Apple about removing account balance. Apple will keep the balance.
If you cannot empty your account balance you will have to create a new Apple Account in your new country.
● Subscriptions
Make sure all subscriptions have been canceled (see: Cancel a subscription from Apple - Apple Support ) and have fully expired. If you do not want to wait, you will need to contact Apple and request any ongoing items you have to be ended immediately.
● Payment Methods.
In the first link above, Apple says: "You might need to enter a valid payment method for your new country or region.” Refer to the list in: Payment methods that you can use with your Apple Account - Apple Support Note that some payment methods in that list may not be acceptable to set as a payment method for country change purposes; for example, account balance. While Apple has through the years avoided making any unequivocal statement about the country origins of such a payment method, using one from a financial institution in your new country may be the easiest way to ensure you don’t run into problems.
● Pending purchases and refunds
If you have pending purchases, or refunds in the process of being returned to you, you will have to wait until these clear. You can canel a pre-order (see: View or cancel pre-orders for apps, movies, music, or books - Apple Support )
● Leave or disband any Family Sharing groups.
Refer to How to leave or remove a member from a Family Sharing group - Apple Support
● Read this support article If your Apple ID or other options are greyed out in Settings —> If you can't sign out due to restrictions, or your Apple Account is grayed out in Settings - Apple Support
For items where you need to contact Apple to resolve an issue, see if there are options for a live chat or telephone call at the bottom of this page --> Contact Apple Support - Apple Support Select your country. Not all countries have all options and telephone numbers tend to only work when calling from the same country.
